The present invention relates to a device for mechanically cleaning fluids, in particular, for cleaning the cooling water entering a heat exchanger, having a segment of pipe as housing, a sieve element essentially covering the cross-section of the pipe segment, with a suction device, moveable around an axle on the influx side for suctioning off the surface area and in this manner cleaning the sieve element.
This type of device is already known from DE 39 17 520 C2.
The device known from this document is a further development and improvement of a device known from DE 36 40 638 C1; see also the parallel device known from EP 0 268 752 A1, in which the cutting plane of the rotationally symmetrical filter is arranged on a cross sectional plane of the feed pipe, for example, in a wall connection. The jet of the aspirating device is capable of being rotated around the middle axle of the feed pipe by an electrical motor, where the motor is arranged on the drainage side of the sieve element inside the feed pipe. This arrangement inside the feed pipe impedes access from the outside to the drive motor, as well as, access to the mounting/suspension and the seal.
In DE 38 01 015 A1, a wheel-shaped filter element is in the cross-sectional plane of the feed pipe. In order to clean the sieve, it is mounted in such a way that it can be rotated around the axle of the filter housing and an aspirating element extending along a radius of the filter element is arranged on the feed side of the filter element and is connected to the drainage pipe. In this case, the entire sieve has to be rotated, which necessitates an extensive array of sprockets and cogwheels made of highly non-corrosive materials. In addition, particles of dirt can settle on the edges of the teeth of the gears and cause locking. Moreover, the flat sieve plate requires extensive reinforcement. Since the fluid to be cleaned is usually sea-water, very expensive materials have to be utilized.
In this respect, the arrangement mentioned initially, according to DE 39 17 520 C2, already represents an advancement, albeit, one has to accept the disadvantage, that the mesh surface area of the sieve has a geometrically complicated shape and can only be manufactured with very costly technical production methods.
This disadvantage also holds true for DE 36 40 638 C1. In addition, it can be said about this document, that, in this case, the pipe cross section is divided into sectors and the aspirating device has the shape of one of the sectors, wherein the aspirating pipe runs along the middle of the pipe, so that the backwash of the sieve is stronger in the vicinity of the aspirating pipe while in the vicinity of the outer wall that has the larger mesh surface area of the sieve, the aspiration is weaker. In conditions of severe accumulation of detritus, the reduced intensity of the back wash in the vicinity of the outer surface of the pipe wall is insufficient to remove the detritus from the surface of the sieve and carry it away.
Each of the U.S. Pat. Nos. 2,275,958 and 1,977,601 describes an apparatus in which the actual filtering process takes place in a housing, which is cast. The sieve is mounted so that it is accessible by way of a lid and the mesh area of the sieve is cleaned by a rotating suction device. The axle of rotation is encased by a cylindrical sieve element and is perpendicular to the pipe axle of the incoming pipe in its own, complex casing, in which fluid passes through the sieve element from the inside to the outside. The drive motor is located advantageously outside of the feed pipes and can, therefore, be accessed from the outside, together with the seals and the support system.
The objective of the invention is to improve on the device mentioned at the beginning, in such a manner, that manufacturing it is simplified and less expensive and that the manner of operation is not changed for the worse.
This objective is achieved in that the sieve element forms a partially cylindrical casing, wherein the axle of the cylinder is perpendicular to the axle of the pipe segment and the open part of the partially cylindrical casing is arranged toward the influx side.
This arrangement will achieve, for one thing, that similar to the U.S. Pat. Nos. 2,275,958 and 1,977,601 as well as to DE 39 17 520 C2, the document chosen as related art, the drive motor for the suction device, capable of being rotated around an axle, is also located outside of the pipe segment and, therefore, is easier to access and service. In addition, an arrangement of this type does not necessitate a complicated type of housing for the device as described in U.S. Pat. Nos. 2,276,958 or in 1,977,601, nor is a complicated type of sieve necessary, as shown in DE 36 40 638 C1, which can only be manufactured by a very costly technical process.
In contrast to this, the device according to the invention uses a sieve with a symmetrical shape which can be easily manufactured, namely, a (partially) circular shape, if necessary, complemented by straight extensions attached to the partial circle.
In order to accommodate the necessary mesh surface area of the sieve and keep the flow-through resistance small, it is advantageous, if, according to a further development of the invention, the housing is enlarged, so that the pipe segment has a region with a larger diameter than the adjoining sealing pipe, wherein, according to a further development, the pipe segment is composed of two partial pipe segments that are coupled together, these partial pipe segments extending conically in a direction facing each other, wherein, these partial pipe segments are connected with joiner pipes by flanges. According to another alternative, the undivided pipe segment has a larger diameter. In this manner, the necessary mesh surface area of the sieve can be successfully provided for in both of the alternatives. In the embodiment having cone-shaped pipe segments, according to a further development of the invention, a round holding plate with a rectangular opening is arranged between the two sections, the edge of the open end of the partially cylindrical casing being fastened to this holding plate so that this partially cylindrical casing covers the rectangular opening. According to another development of the invention, the partially cylindrical casing is closed by side walls through which the axle of the rotating or oscillating motor of the suction device is placed. According to further developments, these side walls can be constructed either completely closed or also as a sieve.
According to another development of the invention, the rotor of the suction device is connected on one side to a drive motor and on the opposite side to an aspirating pipe, through which the waste water together with the aspirated detritus can be disposed of.
The sieve can be provided with webs, however, according to a further development of the invention it can also be constructed without webs. If sieves with webs are used, then it is advantageous, according to another development of the invention, if the sieves provided with webs form chambers, by way of the webs, with a specific length and width, and if the open end of the suction pipe has the same length and width as these chambers. By way of this adaptation, each chamber created in this manner can be sealed, thus creating a strong reflux and securing the disposal of the detritus.
The webs have the advantage that large pieces of detritus, such as stones, mussels, fish etc, can be deposited on the sieve between the webs without disturbing or hindering the rotating motionxe2x80x94it can also be an oscillating, swinging motionxe2x80x94of the aspiration rotor.
The mesh surface area of a sieve provided with webs can be constructed out of flat sieve plates placed together, thereby forming a polygon. This is advantageous if the sieve cannot be bent into a cylindrical shape by conventional milling. It is also advantageous, when using a sieve with webs having various heights, that the center of the sieve is arranged different from the center of the rotor.
In order to hold together the cross-sectional flow of the aspiration rotor, it may be beneficial to divide it into two aspirating pipes or aspirating channels/conduits. It is advantageous in the embodiment having two rectangular aspiration pipes that these are annealed out of two tins and are welded together with a half-rounded turned edge in the area connecting with the waste water pipe.
This results in a particularly advantageous, finished product.
Equipping the device according to the invention allows two pressure relief plates to be provided without great cost that function as by-pass conduits. This construction enables the rotor to move either in an oscillating or rotating manner.
The cross-section of the sieve element can be a semi-circle with attached, straight extensions that are parallel to each other (U-form). This results in a greater mesh surface area of the sieve and, thus, decreased pressure reduction.
If two or more sieve elements are provided, the result is an increased reliability through redundance. Changing seals and maintenance of the individual sieve elements is possible while the other sieve element remains in operation. In addition, the length of construction is reduced, which facilitates the modernization of conventional cooling water filters, since there is usually little space at one""s disposal.
According to still another development, the holding plates in the region at the end of the cylindrical sieve casing jut into the cross-sectional flow, this results in areas of turbulence TK. The turbulence thus created in the flow causes the unbent part of the sieve to clean itself, for example, the sieve element which is U-shaped in cross-section.
In the embodiment without inner segmental ribs, large volumes of detritus can be moved by the rotor until the suctioning orifice of the rotor is clear and the detritus can be aspirated.
The invention is more clearly described using exemplary embodiments, which are illustrated in the drawings.